Nearly ten years ago there was a similar request for that gear on one of the Google Groups. At that time the Airex/Target 360 was a common RV antenna and parts were stocked by most dealers. As I remember, your antenna was made by The Scott & Fetzer Company and sold
under the brand name Airex. (Not the same as the trailer manufacturer.) Target 360 as the model name. Scott & Fitzer was acquired by Berkshire Hathaway Inc. and Airex was probably sold
to Philips Lighting
. They still market at least one TV antenna with the "AIREX COLORMASTER" brand name. The original company, if still in existence, no longer makes antennas but may be making awnings for RVs under the name Carefree of Colorado.
The trail of ownership is so convoluted that I doubt that you will ever find the parts source. Your best bet will be to find a large RV dealer that has been in business for twenty years or more.